What illnesses can affect a rat? - briefly
Rats commonly develop respiratory infections (e.g., Mycoplasma pulmonis), bacterial diseases such as Salmonella and Streptococcus, viral agents like Sendai virus and rat coronavirus, parasitic infestations (mites, pinworms), and neoplastic conditions including mammary adenocarcinomas. Additional frequent problems are gastrointestinal ulceration, renal disease, and metabolic disorders such as diabetes.
What illnesses can affect a rat? - in detail
Rats are susceptible to a wide range of infectious and non‑infectious conditions. Bacterial agents frequently encountered include Salmonella spp., which cause gastroenteritis marked by diarrhea, dehydration, and lethargy; Streptococcus spp., responsible for respiratory infections with nasal discharge and labored breathing; and Clostridium spp., producing enterotoxemia that leads to sudden death after rapid onset of abdominal pain and shock. Diagnosis relies on culture or PCR, and treatment typically involves appropriate antibiotics guided by sensitivity testing.
Viral diseases affect laboratory and pet rats alike. Sendai virus induces upper respiratory signs such as sneezing, serous nasal discharge, and secondary bacterial pneumonia; supportive care and isolation limit spread. Rat coronavirus (RCV) produces sialodacryoadenitis, characterized by swollen lacrimal and salivary glands, conjunctivitis, and reduced appetite; recovery occurs within two weeks, but stress exacerbates severity. Poxvirus infections present as cutaneous lesions and ulcerations; antiviral therapy is limited, emphasizing hygiene and quarantine.
Fungal infections are less common but can be severe. Aspergillus spp. cause pulmonary aspergillosis, presenting with weight loss, cough, and dyspnea; antifungal agents such as itraconazole improve prognosis when administered early. Dermatophytes, notably Trichophyton mentagrophytes, produce alopecia and crusted skin; topical antifungals combined with environmental decontamination are required.
Parasitic infestations include internal and external agents. Hymenolepis nana (dwarf tapeworm) leads to abdominal distension, poor growth, and occasional diarrhea; praziquantel eradicates the parasite. Syphacia muris (pinworm) causes perianal itching and tail-biting; ivermectin or pyrantel pamoate are effective. Ectoparasites such as Myobia musculi (fur mite) produce intense scratching and hair loss; topical acaricides resolve infestations.
Metabolic disorders arise from dietary imbalances or genetic predisposition. Hypovitaminosis E manifests as muscular weakness, ataxia, and retinal degeneration; supplementation restores normal function. Diabetes mellitus, though rare, presents with polyuria, polydipsia, and weight loss; insulin therapy controls glycemia. Renal insufficiency results in azotemia, reduced urine output, and lethargy; fluid therapy and dietary modification support renal function.
Neoplastic conditions are common in aged rats. Mammary adenocarcinomas appear as palpable masses on the ventral thorax, often metastasizing to lungs and liver; surgical excision combined with chemotherapy extends survival. Lymphosarcoma produces generalized lymphadenopathy, weight loss, and anemia; chemotherapy regimens provide limited benefit.
Environmental factors contribute to disease. Poor ventilation and high ammonia levels predispose to respiratory distress and ulcerative dermatitis. Overcrowding facilitates transmission of infectious agents. Adequate cage cleaning, proper nutrition, and routine health monitoring reduce incidence of most conditions.
Early identification of clinical signs, laboratory confirmation, and prompt therapeutic intervention are essential for effective management of rat health problems.